Nanowire-containing multilayer composite thin film plated steel belt and preparation method thereof

Abstract

The invention discloses a nanowire-containing multilayer composite thin film plated steel belt and a preparation method thereof. The steel belt is specifically applied to a battery outer shell material of a mercury-free alkaline battery, a lithium ion battery, a nickel-metal hydride battery and the like and also applied to the field of chemical industry, electrons, packaging, magnetic materials and the like. The preparation method comprises the following steps of: on one face of a steel belt serving as a substrate, plating a layer of micron-crystalline nickel as an outer bottom layer in a DC plating way, wherein the face corresponds tothe outer surface of a battery shell, plating a layer of micron-crystalline nickel serving as an outer middle layer in a pulse plating way, and plating a layer of nano-crystalline nickel-cobalt alloy layer serving as an outer surface layer in a pulse injection plating way; and on one face of the steel belt corresponding to the inner surface of the battery shell, plating a layer of micron-crystalline nickel coated layer as an inner bottom layer in the DC plating way; plating a layer of nanowire-containing nickle composite thin film as an inner middle layer in the pulse plating way, and plating a layer of nano-crystalline nickel-cobalt alloy layer as an inner surface layer in the pulse injection plating way. The steel belt prepared by the inventionhas the advantages of good corrosion resistance and pressing resistance.

Description

technical field [0001] The invention relates to a steel strip coated with a multi-layer composite film containing nanowires for battery shells and a preparation method thereof. Background technique [0002] In recent years, as people's requirements for battery performance have become higher and higher, the performance of battery shell materials such as alkaline manganese batteries, nickel-metal hydride batteries and lithium-ion power batteries has also attracted more and more attention from professionals. As a sealed container, the alkaline manganese battery casing is required to have sufficient corrosion resistance due to the filling of strong alkaline electrolyte. In addition, in the alkaline manganese battery, the battery casing also acts as the positive electrode collector of the battery, so the internal resistance of the battery casing is also an important factor affecting the performance of the battery. In addition, the battery casing also participates in the reaction...

AI Technical Summary

Problems solved by technology

The deformation resistance of the battery case during the stamping process is very large. If the bonding force between the coating and the substrate is not good, it is easy to cause the coating to fall off.

In addition, if the powdering performance of the coating is poor, that is, the coating forms more powder during the thinning and stretching process, and these powders adhere to the punch, which will cause defects on the side wall of the battery case

[0011] The existing surface treatment technologies for steel strips for battery casings are all designed for a single nickel coating or a double-layer film with a simple structure.

The disadvantage of these technologies is that while the treated steel strip has some advantages, it also has some disadvantages that greatly affect the performance of the battery case.

For example, the traditional nickel-plated steel strip has good corrosion resistance and good bonding with the substrate, but its pulverization performance is poor, that is, it is easy to form powder during the stamping process

For steel strips coated with nickel and nickel-cobalt alloys, due to the high hardness of nickel-cobalt alloys, the hardness values ​​of the coating and the substrate do not match, and the coating is prone to peeling off during the stamping process. In addition, the coating with high hardness often has a higher Internal stress, which will reduce the toughness of the coating and cause the coating to become brittle

The steel strip coated with nickel and nickel-bismuth alloy has good alkali corrosion resistance, but due to the poor conductivity of bismuth, the internal resistance of the battery case is large

The steel strip coated with nickel and nickel-tin alloy has small internal resistance, but due to the poor alkali corrosion resistance of nickel-tin alloy, the discharge performance will deteriorate after the battery case is in contact with the alkaline electrolyte for a long time

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